There's considerable imprecision in any future-product plan, but a source at JeepTrackhawkForums indicates that the current plan is for both HEMI engines to end their run in 2019. Both the 6.4-liter and supercharged 6.2-liter units will be supplanted by twin-turbo four or twin-turbo six-cylinder engines, depending on the vehicle.

These unconfirmed reports make sense, with impending CAFE requirements that will almost certainly make V-8 engines a rarity--especially for automakers without big electric-car credits to apply against them.

If the Hellcats and HEMIs die after the 2018 model year, all the tire-smoking versions we've sampled in the past few years would undoubtedly become collectors' items.